From b885aa903c313644f7ba8d46d4c09ead1b52f1f1 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 1 Jul 2025 17:38:38 +0100 Subject: netfs: Provide helpers to perform NETFS_RREQ_IN_PROGRESS flag wangling Provide helpers to clear and test the NETFS_RREQ_IN_PROGRESS and to insert the appropriate barrierage. Signed-off-by: David Howells Link: https://lore.kernel.org/20250701163852.2171681-4-dhowells@redhat.com Tested-by: Steve French Reviewed-by: Paulo Alcantara cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner --- fs/netfs/internal.h | 18 ++++++++++++++++++ fs/netfs/misc.c | 10 +++++----- fs/netfs/read_collect.c | 4 ++-- fs/netfs/write_collect.c | 4 ++-- 4 files changed, 27 insertions(+), 9 deletions(-) --- a/fs/netfs/internal.h +++ b/fs/netfs/internal.h @@ -275,6 +275,24 @@ static inline void netfs_wake_rreq_flag( } /* + * Test the NETFS_RREQ_IN_PROGRESS flag, inserting an appropriate barrier. + */ +static inline bool netfs_check_rreq_in_progress(const struct netfs_io_request *rreq) +{ + /* Order read of flags before read of anything else, such as error. */ + return test_bit_acquire(NETFS_RREQ_IN_PROGRESS, &rreq->flags); +} + +/* + * Test the NETFS_SREQ_IN_PROGRESS flag, inserting an appropriate barrier. + */ +static inline bool netfs_check_subreq_in_progress(const struct netfs_io_subrequest *subreq) +{ + /* Order read of flags before read of anything else, such as error. */ + return test_bit_acquire(NETFS_SREQ_IN_PROGRESS, &subreq->flags); +} + +/* * fscache-cache.c */ #ifdef CONFIG_PROC_FS --- a/fs/netfs/misc.c +++ b/fs/netfs/misc.c @@ -356,14 +356,14 @@ void netfs_wait_for_in_progress_stream(s DEFINE_WAIT(myself); list_for_each_entry(subreq, &stream->subrequests, rreq_link) { - if (!test_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags)) + if (!netfs_check_subreq_in_progress(subreq)) continue; trace_netfs_rreq(rreq, netfs_rreq_trace_wait_queue); for (;;) { prepare_to_wait(&rreq->waitq, &myself, TASK_UNINTERRUPTIBLE); - if (!test_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags)) + if (!netfs_check_subreq_in_progress(subreq)) break; trace_netfs_sreq(subreq, netfs_sreq_trace_wait_for); @@ -400,7 +400,7 @@ static int netfs_collect_in_app(struct n struct netfs_io_subrequest, rreq_link); if (subreq && - (!test_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags) || + (!netfs_check_subreq_in_progress(subreq) || test_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags))) { need_collect = true; break; @@ -454,7 +454,7 @@ static ssize_t netfs_wait_for_in_progres } } - if (!test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags)) + if (!netfs_check_rreq_in_progress(rreq)) break; schedule(); @@ -525,7 +525,7 @@ static void netfs_wait_for_pause(struct } } - if (!test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags) || + if (!netfs_check_rreq_in_progress(rreq) || !test_bit(NETFS_RREQ_PAUSE, &rreq->flags)) break; --- a/fs/netfs/read_collect.c +++ b/fs/netfs/read_collect.c @@ -220,7 +220,7 @@ reassess: stream->collected_to = front->start; } - if (test_bit(NETFS_SREQ_IN_PROGRESS, &front->flags)) + if (netfs_check_subreq_in_progress(front)) notes |= HIT_PENDING; smp_rmb(); /* Read counters after IN_PROGRESS flag. */ transferred = READ_ONCE(front->transferred); @@ -447,7 +447,7 @@ void netfs_read_collection_worker(struct struct netfs_io_request *rreq = container_of(work, struct netfs_io_request, work); netfs_see_request(rreq, netfs_rreq_trace_see_work); - if (test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags)) { + if (netfs_check_rreq_in_progress(rreq)) { if (netfs_read_collection(rreq)) /* Drop the ref from the IN_PROGRESS flag. */ netfs_put_request(rreq, netfs_rreq_trace_put_work_ip); --- a/fs/netfs/write_collect.c +++ b/fs/netfs/write_collect.c @@ -240,7 +240,7 @@ reassess_streams: } /* Stall if the front is still undergoing I/O. */ - if (test_bit(NETFS_SREQ_IN_PROGRESS, &front->flags)) { + if (netfs_check_subreq_in_progress(front)) { notes |= HIT_PENDING; break; } @@ -434,7 +434,7 @@ void netfs_write_collection_worker(struc struct netfs_io_request *rreq = container_of(work, struct netfs_io_request, work); netfs_see_request(rreq, netfs_rreq_trace_see_work); - if (test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags)) { + if (netfs_check_rreq_in_progress(rreq)) { if (netfs_write_collection(rreq)) /* Drop the ref from the IN_PROGRESS flag. */ netfs_put_request(rreq, netfs_rreq_trace_put_work_ip);